A diffractive/refractive lenslet array incorporating a second aspheric surface

摘要

A short focal length image sensor comprising:a color photosensor array comprised of sets of three photosensors with red, green, and blue, filters positioned over respective photosensors in each set;a lenslet array corresponding in the number of lenslets to the number of sets of photosensors in said color photosensor array, wherein each lenslet is formed with a first convex, spherical surface having diffractive means incorporated thereon and a second surface which is aspheric, substantially opposite said first surface with the size of said lenslet array being greater than the size of said photosensor array by an amount that allows the local optical axis of each lenslet at the largest field angle to image incident light onto the set of photosensors associated with the image sensors largest field angle; andan array of aperture stops combined with an array of field stops wherein the number of field and aperture stops corresponds to the number of lenslets and wherein each field and aperture stop is aligned to the center of the local optical axis for an associated set of photosensors.